42 4-51. In an RC differentiator, which of the following waveforms has the shortest time constant? 1. 2. 3. 4. 4-52. In a short time-constant integrator circuit, the maximum amplitude of the input pulse is 100 volts and the time constant of the circuit is 1/10 the duration of the input pulse. At the end of three time constants, what is the maximum voltage across the capacitor? 1. 36.8 volts 2. 63.2 volts 3. 86.5 volts 4. 95 volts 4-53. In a medium time-constant circuit, the maximum amplitude of the input pulse is 100 volts and the pulse length is one time constant. At the end of two time constants, what is the maximum voltage across the capacitor? 1. 23.3 volts 2. 48.4 volts 3. 71.7 volts 4. 100 volts 4-54. In a short time-constant differentiatorcircuit, the maximum amplitude of the input pulse is 100 volts and the time constant of the circuit is 1/10 that of the input pulse. At the end of four time constants, what is the maximum voltage across the resistor? 1. 5 volts 2. 2 volts 3. 23.3 volts 4. 48.4 volts 4-55. In an RC differentiator circuit, the time constant for the circuit and the input pulse are equal. At the end of one time constant, to what maximum percentage of the applied voltage is the capacitor charged? 1. 5 percent 2. 13.5 percent 3. 36.8 percent 4. 63.2 percent 4-56. In an RC network that is used as a coupling circuit, (a) across what component is the output normally taken and (b) what is the relative length of the time constant? 1. (a) Capacitor (b) short 2. (a) Capacitor (b) long 3. (a) Resistor (b) long 4. (a) Resistor (b) short